The present invention relates in general to a safety device and more specifically to a safety device for use with a vehicle.
With the advent of increasingly faster modes of transportation, vehicle manufacturers have increased the amount of protection afforded by a vehicle, both in the number of safety devices and in the sophistication of each safety device. To further encourage vehicle manufacturers to incorporate safety features in their products, the federal government has often promoted safety legislation which mandate varying degrees of safety for vehicles, including automobiles. Among other such mandates as crash resistant bumpers on autombiles and seat belts for passengers in automobiles, current federal legislation has focused on the incorporation of passive restraint devices in automobiles, one such restraint device being an air bag.
Air bags, as passive restraint devices for automobiles, are inflatable during an automobile accident by a source of pressurized fluid. These devices have generally fallen into two categories; inflation from those expansion processes employing reactive or explosive means for inflating, and inflation from expansion processes involving the liberation of pre-pressurized gasses contained within a pressure vessel.
Air bag devices have been developed which pertain to the latter liberation of gasses. Two such devices by Okada, U.S. Pat. No. 4,203,616 and U.S. Pat. No. 4,289,327, appear to disclose an air bag mechanism with a pre-pressurized canister separated from the air bag by a frangible member. The frangible member is dependent on a pressing lid for support. Upon impact of a vehicle, a mechanism causes the pressing lid to move, thereby allowing pressure within the canister to rupture the frangible member. Another device by Hirbod, U.S. Pat. No. 4,215,878, appears to disclose a bumper-air bag system having three valve mechanisms connected to a vehicle bumper. Movement of the bumper during a collision appears to build up pressure to a level which ruptures a diaphragm and liberates pre-pressurized gasses.
Weman, U.S. Pat. No. 3,927,901, appears to disclose a vehicle air bag system with several air bags all interconnected to a pressurized air tank. Impact causes the generation of a pressure wave within the tank which propagates throughout the tank towards the valves and causes the valves to open, thus inflating an air bag. Hodges, U.S. Pat. No. 2,755,125, Sandor, U.S. Pat. No. 2,931,665, and Lee et al., U.S. Pat. No. 4,258,931, all appear to disclose other air bag devices which inflate an air bag using pre-pressurized air stored in a container.
The above described devices rely on either pressure differential to rupture a seal or pressure-activated valves to release pre-pressurized air stored in a pressure vessel. Because both pressure-ruptureable seals and pressure-activated valves do not positively release air from a storage container, a need exists for an improved safety device for use with a vehicle that employs a positive release mechanism to release a source of pressurized fluid and inflate an air bag.